Fighting ignorance since 1973.(It's taking longer than we thought.)

Can the candirú fish swim upstream into your urethra (revisited)?

September 7, 2001

Dear Cecil:

This is in reference to your column "Can the candirú fish swim upstream into your urethra?" (May 19, 2000). I recently heard a talk by a visiting scholar who was researching the candirú. The speaker was collaborating with a South American medical doctor who completed a candirú removal operation in 1997. The fish had entered the (male) patient's urethra, had been stopped by the urethral sphincter (if that's the right term), and had turned at a right angle and burrowed into the scrotum. The fish had died, and the subsequent relaxation of its spines facilitated removal. A photograph of the removed fish and part of the affected area (!) was presented. According to the speaker, the patient claimed the fish had swum out of the water up his urine stream. I thought this might be of interest.

zut, via the Straight Dope Message Board

Illustration by Slug Signorino

Cecil replies:

I’ll say it’s of interest. In my original column I expressed skepticism about Willy-in-the-willy, noting an absence of firsthand or even secondhand accounts. And now here’s a guy with eight-by-ten glossy photographs! I’ve been in contact with Paulo Petry, the scientist you heard, who related the following astonishing tale. Warning — gross-out quotient: high.

Petry is an expert in neotropical ichthyology and vice president of Bio-Amazonia Conservation International, a not-for-profit conservation group. While working in the Amazon city of Manaus, Brazil, he noticed a hubbub in the press about Anoar Samad, a urogenital surgeon who’d performed the world’s first confirmed removal of a candirú from a human penis. What’s more, Samad had a live patient and a dead fish to prove it. Petry decided the world needed to know about this. Here’s an except from an article the two are coauthoring with fish physiologist Stephen Spotte:

On 28 October 1997, one of us (Samad) attended a 23-year-old man from the town of Itacoatiara on the Amazon River who sought medical attention with obstruction of the urethra, having been attacked by a candirú. Prior to being attended, the patient remained untreated for three days and was only administered medication for pain. By the fourth day the patient presented with fever, intense pain, scrotal edema [swelling of the scrotum], and extreme abdomen distention from urine retention. Surgical removal of the fish was considered, but rejected in favor of endoscopy [insertion of a TV-equipped tube into the urethra]. The patient was anesthetized with 5% lidocain and the procedure was performed. The fish was grasped using an alligator-clip attachment on the endoscope and removed in one piece. Fortunately the fish was dead, and decay was beginning to soften its tissues. Tension on the spines had relaxed in death, and they no longer gripped. Had the candirú been alive, its removal would have been more difficult and resulted in greater trauma to the patient. The fish penetrated the victim’s urethra while he was standing in the river urinating, actually emerging from the water and entering his penis, filling the entire anterior urethra [emphasis added]. He reported trying to grab hold of the fish, but it was very slippery, and it forced its way inside with alarming speed. The candirú’s forward progress was blocked by the sphincter separating the penile urethra from the bulbar urethra. With the passage blocked, the fish had made a lateral turn and bitten through the tissue into the corpus spongiosum, creating an opening into the scrotum. Perfusion [flushing] of the urethra with sterile distilled water prior to endoscopy induced further immediate and pronounced scrotal edema, making it evident that the opening had allowed the perfusate to enter the scrotum. Although the patient had remembered the fish as being small, after extraction it measured 134 mm (5½ in) [long], with a head width of 11.5 mm (7/16 in) … Some coagulated material was removed, revealing a wound on the bulbar urethra of 1 cm in diameter and associated with a small amount of local bleeding. Although the patient suffered immediate trauma, no long term effects of the attack were noticed 1 year after the incident.

Petry insists this is no joke. The operation is well documented, with photos, a videotape of the procedure, medical reports, and of course the fish, which was donated to an Amazon research institute. (The species couldn’t be identified precisely due to decay. I can’t decide what’s worse: having a live fish inside your penis or a rotting dead one.)

“The description of the case follows exactly what the patient said,” Petry tells me. “According to him, he was standing in the water thigh deep, urinating with his penis out of the water yet close to it. The fish jumped and entered his urethra. He repeated the same version more than once when asked to describe the incident to Dr. Samad.”

Research by Petry and Spotte found no indication that the fish is particularly attracted to urine. Petry adds, “The only way that the fish could enter the urethra is while it is expanded during urination, otherwise I don’t think it could move in.” One shudders, but I thought you’d want to know.